So it looks like some states are refusing to share data with the Advisory Commission on Election Integrity, even though in many of them the data is publicly available --"anybody can walk in off the street and get the data."
You're an "anybody." Here is a list of the states, and whether or not they are willing to provide public information to the commission. If you live in a state where information available to the public is being withheld, you can request it and pass it along. (There may be a fee, it varies by state, but you can find out.)
http://www.pbs.org/newshour/rundown/trump-commission-requested-voter-data-heres-every-state-saying/